1. Field of the Invention
The present invention relates to a power module substrate used in a semiconductor apparatus that controls a large current and a high voltage, a power module substrate with a heat sink, a power module, and a method of manufacturing a power module substrate.
Priority is claimed on Japanese Patent Application Nos. 2011-176712 and 2011-176881, filed Aug. 12, 2011, the contents of which are incorporated herein by reference.
2. Description of Related Art
Among semiconductor devices, a power module that supplies power has a relatively high amount of heat generation. Therefore, as a substrate on which the power module is mounted, for example, a power module substrate, which is provided with an insulating substrate formed from AlN (aluminum nitride), Al2O3 (alumina). Si3N4 (silicon nitride), or the like, a circuit layer that is formed by bonding a first metal plate onto one surface side of the insulating substrate, and a metal layer that is formed by bonding a second metal plate onto the other surface side of the insulating substrate, is used.
In the above described power module substrate, a semiconductor device such as a power device is mounted on the circuit layer through a solder material.
For example, PTL 1 suggests a power module substrate which is formed by using an aluminum plate as the first metal plate (circuit layer) and the second metal plate (metal layer).
In addition. PTL 2 and PTL 3 suggest a power module substrate which is formed by using a copper plate as the first metal plate (circuit layer) and the second metal plate (metal layer), and by directly bonding the copper plate onto the insulating substrate according to a DBC method. In addition, in FIG. 1 of PTL 2, a power module substrate with a heat sink in which an aluminum heat sink is bonded to the above-described power module substrate using an organic heat resistant adhesive is disclosed.